Is incidental prophylactic oophorectomy an acceptable means to reduce the incidence of ovarian cancer?

According to previous reports, the lifetime risk of developing ovarian carcinoma is 1.4%. This figure varies with age from 6.6 per 100,000 among women aged 35 to 39 years up to 55.1 per 100,000 among women aged 75 to 79 years. Prophylactic oophorectomy remains a modality to decrease the incidence of ovarian cancer. What proportion of women diagnosed with an ovarian malignancy had a preceding laparotomy at which time a prophylactic oophorectomy could have been performed? METHODS: We reviewed the new ovarian cancer diagnoses seen in patients between August 1988 and August 1993 at the Ottawa Regional Cancer Foundation. Four hundred and four patients were identified. These patients were analyzed for preceding abdominal surgery, age, time to disease progression, time to death, time to death from other causes, and average follow-up. The previous abdominal surgeries were divided into: (1) major gynecological surgery; and (2) general surgery procedures, which were further divided into laparotomy and pelvic surgery (group A surgeries) and general surgery that included other abdominal surgeries tie, appendectomy, cholecystectomy) where access to the pelvis could be more difficult (group B surgeries). RESULTS: A total of 270 abdominal surgeries was performed, prior to the diagnosis of ovarian cancer. The group was stratified according to the timing of the surgery (less than or equal to 40 years, 41 to 45 years, 46 to 50 years, >50 years). Based on these data, and on the grouping of general gynecologic surgeries plus the general surgical procedures of group A, 10.9% of ovarian cancers would have been prevented if prophylactic oophorectomy had been performed in patients who had surgery over 40 years of age; over 45 years this was 6.7%, over 50 years it was 4%. If one adds all major surgeries, including general surgery groups A and B, the results were 26.9% over 40 years of age, 20% over 45, and 16.6% over 50. CONCLUSION: We found that, depending on the age of the patient, prophylactic oophorectomy results in a 4% to 10.9% reduction in the incidence of ovarian carcinoma. This increases to 16.6% to 26.9% if one considers general surgery procedures in which access could be more difficult. Although we are not advocating the frequent use of this procedure, we recommend that surgeons routinely discuss this option before surgery with their postmenopausal female patients over 49 years of age. Given that the decision for prophylactic oophorectomy is multifaceted, we feel that a risk scoring for ovarian cancer and a discussion of the risk and benefit ratio should be undertaken. The ultimate goal is to heighten patient awareness of the risk factors to ensure that an informed decision is made concerning this consistently lethal disease. (C) 1997 by Excerpta Medica, Inc.